Field of the Invention
This invention relates to a Digital Video Broadcasting-Terrestrial (DVB-T) system and its modulation method, and in particular, it relates to such a system that can automatically adjusts the modulation and the resolution of the image.
Description of the Related Art
Conventionally, when using a Digital Video Broadcasting-Terrestrial (DVB-T) system or related technology to transmit video and audio data, the modulating modes of the transmitting end have a fixed setting; the transmitting end sets the settings, and then transmits the signals to the receiving end. For example, a television station sets the relevant parameters, then transmits the signals to the user. However, during signal transmission, due to factors such as distance, noise, and wire quality, the signals may be degraded, causing the receiving end to experience problems such as broken images, interruption, no display, etc.
While these problems may be improved or resolved by manual adjustments, making adjustments manually has also has difficulties. For example, when the distance between the transmitting end and the receiving end is far, it is difficult to realize manual adjustment. Also, when the transmission wires are aged, problems it causes can only be discovered when abnormalities are noticed at the receiving end.